Service suspension basket arrangement

ABSTRACT

The invention relates to a service suspension basket which is adapted to move on rails or similar mounting means which are secured on the under side of platform deck or on a similar, downwardly facing foundation, the service basket is supported via a number of join arm-formed, hydraulically pivotable support means with associated separate hydraulically operated catch claws on the rails or similar mounting means.

The present invention relates to a service suspension basket arrangementwhich is adapted to move on rails or on similar mounting means which aresecured on a support ramp on an upwardly facing foundation and/or onrails or on similar mounting means which are secured on the under sideof a platform deck or on a similar, downwardly facing foundation.

The service basket is particularly intended for use for inspection work,easier maintenance work together with repair work on installations(drilling rigs and the like) at sea in connection with oil and gasfields. It is especially appropriate to use the service basket on theunder side of a deck, the so-called "cellar deck". However, it is alsoappropriate to use the arrangement on land installations.

With the present invention the aim is to be able to carry out theafore-mentioned service operations without using scaffolding and likeconstructions which are relatively cost demanding in purchase and in useand which in addition are time-demanding in connection with assembly anddisassembly. The objective is thus a service basket which can betransferred in a relatively rapid and easy manner from storage locationto use location and which by "self help" can take itself forwards to andbackwards from different positions of interest on the under side of thedeck or similar foundation in a relatively rapid and reliable manner.

The arrangement according to the invention is characterised in that theservice basket is supported, via a number of joint arm-formed,hydraulically pivotable support means with associated separatehydraulically operated catch claws, on the said rails or similarmounting means, a feeler means or a pair of feeler means in each catchclaw controlling the operation of the remaining catch claws and/or thesupport means of the remaining catch claws, so that when the one catchclaw assumes an open or released position there is provision for theassociated feeler means to block the operation of the remaining catchclaws and/or support means of the remaining catch claws.

By means of the joint arm-formed, hydraulically pivotable support meanswith associated separate hydraulically operated catch claw one canaccording to desire allow the service basket to move along or across theassociated rails or similar mounting means or from mounting means tomounting means, for example along the under side of a deck or a roof--orfrom a support ramp on an upwardly facing foundation to the under sideof the deck or the roof--in a controlled manner. That is to say that bymeans of the said feeler means or pair of feeler means one can providefor movement of the support means with associated catch claws one at atime in a controlled and reliable manner. This makes it possible for anoperator in the service basket to move the support means with catch clawin different directions and over different distances from rail to railor from mounting means to mounting means or along the rail or themounting means, while the remaining support means with associated catchclaws maintain the basket in a controlled manner at its associated fixedlocation and with the service basket in one and the same position.Movements of the service basket can take place at a relatively slowtempo.

By services which are to be carried out below a platform deck, forexample below a so-called "cellar deck", there are most often relativelylarge heights between said cellar deck and a so-called "spider deck"lying below. Often the distance in height is 10-12 meters. The aim insuch instances is to allow the service basket in the starting positionto rest on rails or similar mounting means on a support ramp which bearsagainst the upwardly facing side of the spider deck. Thereby one canallow the basket to start its movement upwardly against the downwardlyfacing side of the cellar deck from a level (for example 2 m) above thespider deck. By way of the support means with associated catch claws,which can be operated one at a time, it is possible during the whole ofthe transfer operation constantly to maintain three of the four catchclaws in secure engagement with associated rails or mounting means whilethe remaining catch claw shifts fastening grip. Provision is made foreach support means in an outstretched condition to have a length of, forexample, 4 m, and the service basket can then be lifted first fourmeters above the support frame and thereafter catch hold of the rails ormounting means of the cellar deck four meters above the basket.

Further features of the arrangement according to the invention will beevident from the following description having regard to the accompanyingdrawings, in which:

FIGS. 1 and 2 show the service basket with associated support means andcatch claws illustrated from the side and from above, respectively.

FIGS. 3 and 4 show a catch claw, seen from the side in respective closedand open positions in connection with a rail or similar mounting means.

FIGS. 5 and 6 show the catch claw according to FIG. 3 seen from thefront side and from the back side, respectively.

FIGS. 7-15 show schematically different positions which the servicebasket assumes during transfer of the latter from a parked position onan upwardly facing foundation to a service position on a downwardlyfacing foundation.

In FIGS. 1 and 2 there is illustrated a service basket 10 with spacefor, for example, two men, that is to say a trained and authoriseddriver and an operator for carrying out inspection, repairs, maintenanceand the like. The basket 10 is provided with a box-shaped tubularframework 11 having a closed bottom 12 with a protective fence on forexample three of the sides and protective fence 13 with associated gate14 on the fourth side. The upper half of the service basket is withoutfence and is without covered roof, but has a roof frame in order toprevent persons in the basket from being pressed too high upwardsagainst the under sides of a deck or roof. At the top of the basket 10there are arranged fastening ears 15 for lifting straps with associatedlifting hooks (not shown further) for handling the basket with liftingcrane or similar lifting equipment.

At each of the four corners of the basket there is pivotably mountedabout a vertical axis 17a between the fastening ears 15 and fasteningbrackets 16 lying below a pivot shaft 17. At the upper end of the pivotshaft 17 there is formed a "shoulder joint"-forming pivot bearing, andthere is pivotably mounted about a first horizontal axis 18a in abracket 18 the one end of a first joint arm or a so-called "upper arm"19. At the opposite end the first joint arm 19 is linked via anotherhorizontal elbow joint-forming pivotal axis 19a to another joint arm orso-called "forearm" 20. The opposite end of the joint arm 20 is via aso-called "hand joint"-forming pivot bearing having a third horizontalpivotal axis 20a linked with a support bracket 21 which via a transversepivot axis 21a supports pivotably mounted an associated catch claw 22.Between the basket 10 and the pivot shaft 17 there is inserted a firsthydraulic pressure cylinder 23. Further between the lower end of thepivot shaft 17 and one (inner) end portion of the arm 19 there isinserted another hydraulic pressure cylinder 24. Between said one(inner) end portion of the arm 19 and a corresponding one (inner) endportion of the arm 20 there is inserted a third hydraulic pressurecylinder 25. Correspondingly, there is inserted between the other(outer) end portion of the other arm 20 and the support bracket 21 afourth hydraulic pressure cylinder 26, while between the support bracket21 and the catch claw 22 there is inserted a fifth hydraulic pressurecylinder 27. On said one (inner) end portion of the arm 20 there isfixed a control bow 28 which cooperates with a feeler means 29 fixed tothe first arm 19. Immediately the connection between or the contactbetween the control bow 28 and the feeler means 29 is locally broken,the third pressure cylinder 25 is prevented from further drawing out theassociated piston rod, so that an automatic stopping can be obtained ofthe mutual pivoting of the arms 19, 29 beyond a particular angle andthereby ensure against maximum stretching out of the angle between thearms 19, 20. If desired, the feeler means at such a maximum swinging outof the arms 19, 20 can provide for the interruption of all furthermovement of the combined pressure cylinders 24-27, until normal workingconditions are established by means of controlling associated controlvalves.

In FIG. 3 there is shown the catch claw 22 in a closed position and inFIG. 4 in an open position. The catch claw 22 comprises a first clampmember 31 which is pivotably mounted about a transverse axis 31a on astationary clamp member 32. The outer end of the clamp member 31 and theouter end of the clamp member 32 are respectively provided with supportplates 33, 34 with associated friction-promoting coatings 35, 36. Thesupport plates 33, 34 with associated coatings 35, 36 form supportabutments against the upper side of oppositely directed lower flanges37a and 37b on an I-shaped rail 37 (only the lower portion is shown inFIGS. 3-6), that is to say on each side of the central web 37c of therail. A third clamp member 38 is provided with a support plate 39 withan associated friction-promoting coating 40, which forms a supportabutment against the under side of the flanges 37a, 37b.

The clamp member 31 is constructed of two mutually parallel platemembers 41, 42, which are each in the form of a two-branched lever andwhich comprise a main branch 41a and 42a and an auxiliary branch 41b and42b. The clamp member 32 is correspondingly constructed of two mutuallyparallel plate members 43, 44, one end of which is rigidly connected toa fastening plate 45 which is supported by a pivot 46 which is turnablymounted about the axis 21a in the support bracket 21. The pivot 46 isprovided with a gear rim 46a which cooperates with a rack in thepressure cylinder 27. Opposite ends of the plate members 43, 44 arerigidly connected to each other via the support plate 34. In addition,the plate members 43, 44 are rigidly connected to each other by means oftwo shaft pins 47 and 48. The pivotal axis of the shaft pin 47corresponds to the pivotal axis 31a of the clamp member 31, the clampmember 31 being pivotably mounted on the shaft pin 47 in theintermediate space between plate members 43, 44 of the clamp member 32.Plate members of the clamp member 31 are rigidly connected to each otherat the outer end of the main branch 41a and 42a via the support plate33, while the plate members are connected to each other at the outer endof the auxiliary branch 41b and 42b by means of a shaft pin 49. Theclamp member 38 supports via two ears 38a and 38b a shaft pin 50. Theshaft pin 50 is linked by means of a first pair of support rods 51, 52to a shaft pin 53 which extends between the plate members 41, 42 in theclamp member 31 at the inner portion of the main branch 41a and 42a,while the shaft pin 50 is linked by another pair of support rods 54, 55with the shaft pin 48 on the clamp member 32. Between the shaft pin 48on the clamp member 32 and the shaft pin 49 on the clamp member 31 thereis inserted a compression spring 57 between spring abutments 58, 59, andcentrally within the compression spring there is inserted a hydraulicpressure cylinder 60. Between the shaft pin 50 in the clamp member 38and the shaft pin 47 in the clamp member 32 there is inserted atelescopically collapsible control pin 61.

The opening and closing of the catch claw, that is to say the adjustmentof the clamp members 31 and 38 from the position shown in FIG. 3 to theposition shown in FIG. 4, and vice versa, occurs by means of thehydraulic pressure cylinder 60. In the position illustrated in FIG. 3the pressure cylinder 60 via the support rods 51, 52 provides for theclamping of the clamp member 38 against the under side of the rail 37 atthe same time as the clamp member 31 is clamped against the upper sideof the flange 37a. The pressure cylinder 60 has as shown in FIG. 4provision for pivoting the clamp member 38 as well as the clamp member31 away from the rail 37, while the clamp member 32 still rests againstflange 37b of the rail 37. After the clamp members 31 and 38 arereleased from the rail 37, as shown in FIG. 4, the clamp member 32 canfinally be unhooked from the rail 37.

As shown in FIGS. 3, 5 and 6, the clamp members 31 and 32 support theirrespective plate pieces 62 and 63 equipped with respective feeler means64, 65, which are activated when the clamp members 31, 32 assume theposition which is shown in FIG. 3. On activating the feeler means 64, 65a signal is emitted to a control panel (not shown further) whichindicates that the engagement of the catch claw 22 is secure. Thecontrol panel can in addition to warning lamps and other displayarrangements be provided in the usual way with manually operable leversor push buttons for control valves and the like. In cases of powerfailure or drop of working pressure on the pressure cylinder 60 thecompression spring 57 will immediately take over and safeguard placingthe catch claw in the position which is illustrated in FIG. 3.

The signal which is emitted from the feeler means 64, 65 is ofconsiderable significance in ensuring that one gets a controlledhandling of the basket. Immediately one opens the one catch claw, thefeeler means 64, 65 emit a control signal to the control panel, wherebyhandling of the remaining catch claws is blocked until the opened catchclaw has once again assumed a fresh, controlled engagement and hasemitted a signal for this via the feeler means 64, 65.

In the basket 10 there can be arranged corresponding feeler means 66, 67which oversee that the gate 14 in the basket is closed and which bycorrespondingly giving a signal ensure that none of the catch claws canbe actuated before the gate is closed. Corresponding feeler means (notshown further) can also be arranged in order to sense that the basket atany time has a horizontal position and in order to block furtherhandling of the basket until the horizontal position is reestablished.

In FIGS. 7-15 there are shown various movements which can be effectedwith the basket and its joint arms and associated catch claws.

In FIG. 7 the basket 10 is shown in an inactive, parked position on astand-forming support ramp 70 on an upwardly facing deck 70a (spiderdeck). The support ramp 70 is provided with a pair of lower rails ormounting means 71 and a pair of upper rails or mounting means 72. InFIG. 7 the basket is shown resting against upper mounting means 72 ofthe support ramp, while four joint arm-formed support means 75-78 of thebasket are pivoted downwards and by means of associated catch claws 22are fastened to the lower mounting means 71, 72. The support means 75-78each consist of a pair of arms (upper arm and forearm) corresponding tothe arms 19, 20 with associated pivot shaft 17, support bracket 21 for acatch claw 22, such as described with reference to FIGS. 1 and 2.

In FIG. 8 the basket 10 is shown after the support means 75-78 viaassociated catch claws 22 have assumed in turn and order and separatelya fresh grip on the upper mounting means 73, 74 of the support ramp 70.

In FIG. 9 the basket 10 is shown after the support means 75-78 arestretched out in concert by synchronous movement of associated pressurecylinders in the support means 75-78. So long as all the catch claws 22are in permanent, controlled engagement (inspected by the feeler means64, 65) with associated mounting means or rails, the combined supportmeans can be controlled synchronously with a corresponding pattern ofmovement in order to move the basket in a vertical or horizontaldirection where this is appropriate.

In FIG. 10 there is illustrated the one support means 75 shown raisedupwards for engagement with a rail 37 on the under side of a downwardlyfacing deck 79 (cellar deck). There are shown a series of mutuallyparallel rails 37 with a suitably large intermediate space of, forexample, about 90 cm in a case where each joint arm 19 and 20 in eachsupport means 75-78 has a length of about 200 cm.

In FIG. 11 the basket 10 is shown after the latter is suspended via allof its four support means 75-78 in associated rails 37 in the deck 79,and in FIG. 12 the basket is shown after it is raised upwards to asuitable level for horizontal movement of the basket on the under sideof the deck 79. In FIG. 12, the support means 75-78 are shown in aposition with the "shoulder joint" of the support means closed off at a90° angle to the basket, that is to say with the "upper arm" 19extending horizontally outwards from the basket. In this startingposition the "forearm" 20 of the support means extends obliquely upwardsand inwards towards associated rails 37 in which they are fastened withassociated catch claw or "hand" 22.

In FIG. 13 there is shown a first stage of the movement of the basket 10across the deck 79, that is to say from rail 37 to rail 37, the oneforearm 20 being pivoted outwardly into fresh engagement with a parallelrail. Thereafter a second forearm 20 is pivoted in a correspondingmanner into engagement with the same said parallel rail. Finally thebasket is pivoted sideways to the position which is shown in FIG. 14,and thereafter in turn and order, as indicated in FIG. 14, onesubsequently pivots a forearm of a third and a fourth support means withassociated catch claws laterally into fresh engagement with a new,parallel rail to a position corresponding to FIG. 12. Correspondinglyone can continue laterally from rail to rail over the whole extent ofthe deck 79 in the transverse direction. Similar movements can also beeffected along the rails 37, that is to say in the longitudinaldirection of the deck, there being effected in such an instance a gripshift for a catch claw one at a time and in a particular pattern in amanner similar to that described above for the movement in thetransverse direction, the only difference being that the arms arepivoted sideways about a vertical axis instead of exclusively abouthorizontal axes as described above.

In FIG. 15 the basket 10 is shown in a typical service position afterthe basket has been lifted upwards to a position just below the rails 37in the deck 79.

I claim:
 1. Service suspension basket arrangement (10) which is adaptedto move on rails or on similar mounting means (71, 72) which are securedon a support ramp (70) on an upwardly facing foundation and/or on rails(37) or on similar mounting means which are secured on the under side ofa platform deck (79) or on a similar, downwardly facing foundation,characterized in that the service basket (10) is supported, via a numberof joint arm-formed, hydraulically pivotable support means (75-78) withassociated separate hydraulically operated catch claws (22), on the saidrails (37) or similar mounting means (71, 72), a feeler means or a pairof feeler means (64, 65) in each catch claw (22) controlling theoperation of the remaining catch claws and/or the support means of theremaining catch claws, so that when the one catch claw assumes an openor released position there is provision for the associated feeler meansto block the operation of the remaining catch claws and/or support meansof the remaining catch claws.
 2. Arrangement in accordance with claim 1,characterized in that the support means (75-78) comprise a first jointarm ("upper arm" 19) which with a shoulder joint-forming pivot bearingis linked to the upper portion of the service backet (10) via a verticalpivotal axis together with a first horizontal pivotal axis (18a) andanother joint arm ("forearm" 20) which is linked with an elbowjoint-forming horizontal pivotal axis (19a) to the first joint arm (19)and with a hand joint-forming pivot bearing is linked to the associatedcatch claw (22) about a third horizontal pivotal axis (20a) and apivotal axis (21a) which extends across the third pivotal axis (20a), afirst hydraulic cylinder (23) between the basket (10) and a pivot shaft(17) in the shoulder joint-forming pivot bearing controlling thepivoting of the associated support means (75-78) with associated catchclaws (22) about the vertical pivot axis (17a), while another hydrauliccylinder (24) between the pivot shaft (17) and the first arm (19) and athird hydraulic cylinder (25) between the first arm (19) and other arm(20) together with a fourth hydraulic cylinder (26) between the otherarm (20) and a support bracket (21) for the catch claw (22) control themovement of the catch claw towards and away from and upwards anddownwards respectively in relation to the basket (10), and a fifthhydraulic cylinder (27) between the support bracket (21) and the catchclaw (22) controls the movement of the catch claw in relation to acooperating rail or similar mounting means.
 3. Arrangement in accordancewith claim 2, characterized in that there is arranged between the firstarm (19) and other arm (20) a feeler means (29) for sensing a maximumoutwards pivotal angle between the arms (19, 20) and for emitting asignal for preventing pivoting of the arms (19, 20) beyond a particularmaximum outward pivotal angle.
 4. Arrangement in accordance with one ofclaims 1-3, characterized in that the catch claw (22) comprises a firstclamp member (31) which is pivotably mounted about a transverse axis(31a) on the other clamp member (32) and that the first clamp member(31) is pivoted in a direction towards and away from the other clampmember (32) by means of a hydraulic pressure cylinder (60), and thatthere is arranged a pair of inductive feeler means (64, 65) on each ofthe clamp members (31, 32), arranged just by an intermediate portion(37c) on a cooperating rail (37) or similar mounting means. 5.Arrangement in accordance with claim 4, characterized in that the firstclamp member (31) is pivoted in a direction towards the other clampmember (32) by means of a compression spring (57) in addition to thehydraulic cylinder (60).
 6. Arrangement in accordance with claims 4 or5, characterized in that the catch claw (22), in addition to the firstclamp member (31) and the other clamp member (32), which each form asupport against the one side of the rail (37), is provided with a thirdclamp member (38) which forms a support against the opposite side of therail (37) in order to clamp the rail (37) between the three clampmembers (31, 32, 38).
 7. Arrangement in accordance with claims 5 or 6,characterized in that the first clamp member (31) is designed as atwo-branched lever which is pivotable about the transverse axis (31a) onthe other clamp member (32), and that the compression spring (57) andthe associated pressure cylinder (60) are inserted between a fasteningon the other clamp member (32) and a fastening on the one lever branch(41b, 42b) of the first clamp member (31), and the third clamp member(38) is connected to said fastening on the other clamp member (32) and afastening on the other clamp member (32) and a fastening on the otherlever branch (41a, 42a) of the first clamp member (31) by means of ajoint arm-forming support rods (51, 52; 54, 55), while the third clampmember (38) is preferably controlled via a telescopic control membertowards and away from the transverse axis (31a) on the other clampmember (32).